I use a claro SIM card in a samsung tablet ( so no need for modem ).
Recently the reliability is much better ( less cut offs, cant rember the last time there was no internet as opposed to last year).
Speed is not great but fine for dr1, emails, morning papersep etc......
Videos can be a pain ( but sometimes work fine, depends on ...... god knows what ).
I borrowed one of those modem SIM card thingys to update apps and games on my wife's tablet ( hers has no SIM card slot ).
Worked fine.
Most important is the network reception. I use claro, cos thats all thats available with correct reception in my campo. Pre paid internet. 40 pesos a day for 200 M.